Talking about Balcofish in the EU issue of Sustainability is just fine, since we received European BONUS funds last year. We are one of seven laboratories in Sweden, Denmark and Germany which are working together, says project leader Lars Förlin who is professor at the Department of Zoology, Göteborg University.
- We hope that the results of the project can be used in the long term in improving the environment in the Baltic Sea, adds Joakim Larsson, associate professor of physiology at the Sahlgren Academy at the same university.
The subject is the blenny
The blenny, which at this stage ought to be used to attention, has been specially chosen for the studies. For many years, this species has been one of the favourites of researchers in regard to environmental monitoring of coastal regions.
- The blenny is of special interest since the female does not lay eggs but gives birth to live young. Because of this we have a good measure of the reproductive capacity of each individual female. The blenny also extends along large sections of the Swedish coast and is relatively stationary, explains Lars Förlin.
The fact that the blenny is quite stationary is also an advantage for research. Because if the fish is not healthy, this indicates that this is due to some impact in the area where it was caught. It may, for instance, be a discharge from a certain point source.
In order to find what the physiology of a healthy and well fish is like, fish are regularly caught at the cleanest possible sites in Fjällbacka and Östergötland (Kvädöfjärden). Several studies in polluted areas have witnessed that blenny can be in poor health. DNA damage and malformation have, inter alia, been found in the young of blenny.
Reproduction
Some time ago, Larsson and Förlin found that the blenny population outside the discharge pipe from a pulp factory in Småland had a distorted sex ratio. Far more males than females were born.
More or less active genes. Microarray analyses are mostly used to study how active different genes are in a certain individual or tissue, but they can also be used to study genetic variation, for example between populations from areas of the Baltic Sea that are affected by different kinds of pollutants. The photograph shows a small part of a microarray analysis on fish, performed on Geniom, which is an ultraflexible microarray robot. The intensity of each spot reveals how active a certain specific gene is in the fish. With this technique, global analyses of thousands of genes can be made simultaneously, and this can help find the relationship between exposure to environmental toxins and the biological effects in the fish. Photographer: Lina Gunnarsson
One of the things they are studying in Balcofish is how good blenny are at reproducing, in relation to the extent of their exposure to various environmental toxins.
- We also try to couple the gene expression of the fish to their reproductive capacity, explains Joakim Larsson.
Microarrays
The studies of the blenny by Förlin and Larsson are financed by Formas, EU and the Swedish Environmental Protection Agency. One important element of these is the development of microarray analyses in monitoring wild fish populations.
In one and the same analysis, more than 10,000 genes can be studied simultaneously. A chip the size of a postage stamp is put into an advanced analytical apparatus. All the gene sequences to be studied are on this chip. And the fish sample to be analysed is then affixed to the chip.
- To put it simply, in this way we can find which genes are on and which are not, says Lars Förlin. This can in turn give us information as to which physiological processes have been affected, and perhaps also the type of chemicals the fish had been exposed to.
- We can say that we are fishing with a very large net after information on how pollutants in the environment affect fish, says Joakim Larsson. To be able to fish with this net, it is necessary that we know what a large part of the genetic material is like.
We have quite a good knowledge of humans, and also mice, rats, bacteria and a lot of other species.
- But previously we knew very little about the genes of the blenny, and we have therefore now sequenced a large proportion of their genes, says Joakim Larsson.
Results
Both researchers have a lot of projects in progress at the same time, some individually and some together. They have recently submitted a report on a project that had been supported by both Formas and Mistra and was entitled Pharmaceuticals in the environment – development of biological fingerprints. And in another recently started Formas project, Joakim Larsson’s team will study mice to find how hormone disrupting compounds affect egg and sperm transport.
Lars Förlin and Joakim Larsson promise that they will quite soon publish their findings on what the blenny’s genes look like and how the developed microarray method works. But the other results, on the association between environmental toxins, gene expression and the wellbeing of the fish, will have to wait some time.